Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Wafer Edge Profile Control for Improvement of Removal Uniformity in Oxide CMP

산화막CMP의 연마균일도 향상을 위한 웨이퍼의 에지형상제어

  • Choi, Sung-Ha (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Jeong, Ho-Bin (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Park, Young-Bong (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Lee, Ho-Jun (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Kim, Hyoung-Jae (Dongnam Division, KITECH) ;
  • Jeong, Hae-Do (Graduate School of Mechanical Engineering, Pusan National University)
  • Received : 2011.08.03
  • Accepted : 2011.11.08
  • Published : 2012.03.01
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Abstract

There are several indicators to represent characteristics of chemical mechanical planarization (CMP) such as material removal rate (MRR), surface quality and removal uniformity on a wafer surface. Especially, the removal uniformity on the wafer edge is one of the most important issues since it gives a significant impact on the yield of chip production on a wafer. Non-uniform removal rate at the wafer edge (edge effect) is mainly induced by a non-uniform pressure from nonuniform pad curvature during CMP process, resulting in edge exclusion which means the region that cannot be made to a chip. For this reason, authors tried to minimize the edge exclusion by using an edge profile control (EPC) ring. The EPC ring is equipped on the polishing head with the wafer to protect a wafer from the edge effect. Experimental results showed that the EPC ring could dramatically minimize the edge exclusion of the wafer. This study shows a possibility to improve the yield of chip production without special design changes of the CMP equipment.

Keywords

References

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